How to redirect/rewrite to the FQDN URL without setting ServerName

apache-2.2fqdnhostnamemod-rewriteredirect

Often in intranets, users will direct URLs to a hostname without supplying the FQDN. Example:

http://internalHost

Instead of

http://internalHost.example.com

I would like to redirect users / rewrite URLs so that everything will use the FQDN. Here's the catch: I don't want to set ServerName explicitly. (This is for a product which will be deployed in multiple intranets so we can't know the value of ServerName ahead of time).

According to: http://wiki.apache.org/httpd/CouldNotDetermineServerName Apache uses a reverse lookup to determine a default FQDN.

How can I make use of/reference that FQDN that Apache is using for a mod_rewrite or redirect?

Best Answer

I would suggest you read about UseCanonicalName.

http://httpd.apache.org/docs/current/mod/core.html#usecanonicalname

Probably the option

UseCanonicalName DNS

Should be sufficient (as Apache will by itself already generate a redirect)

De documentation also mentions that UseCanonicalName influences what ends up in the SERVER_NAME variable name, which you could use in a rewriterule.

Correct way in new versions of nginx

Turn out my first answer to this question was correct at certain time, but it turned into another pitfall - to stay up to date please check Taxing rewrite pitfalls

I have been corrected by many SE users, so the credit goes to them, but more importantly, here is the correct code:

server {
       listen         80;
       server_name    my.domain.com;
       return         301 https://$server_name$request_uri;
}

server {
       listen         443 ssl;
       server_name    my.domain.com;
       # add Strict-Transport-Security to prevent man in the middle attacks
       add_header Strict-Transport-Security "max-age=31536000" always; 

       [....]
}

Redirect URL within Apache VirtualHost

Turns out mod_rewrite rules are fine in the VirtualHosts file, apart from the RewriteBase rule. I ended up with this:

<VirtualHost *>
  ServerName www.example.com
  RewriteEngine on
  RewriteCond %{HTTP_HOST} ^www.example.com
  RewriteRule ^/(.*)$ http://example.com/$1 [L,R=301]
</VirtualHost>

EDIT: on the advice of joschi in the comments, I'm now using this simplified version using the Redirect directive from mod_alias:

<VirtualHost *>
  ServerName www.example.com
  Redirect 301 / http://example.com/
</VirtualHost>

Best Answer

Related Solutions

Nginx – In Nginx, how can I rewrite all http requests to https while maintaining sub-domain

Correct way in new versions of nginx

Redirect URL within Apache VirtualHost

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